When the first letter of options of serverMultiselectFilter start with
uppercase or lowercase then they are not sorted in the filter.
As an example we post a snippet
In this snippet if you open the filter of Film Title column you will see that
the values are not sorted from A to Z and this happens because of the
uppecase and lowercase of the first letters.
If you change the first letter to uppercase then the sorting of the
filter will work but its not good this to happen when the Data are
important and should be present as they are.